Filter Photometry¶
The following Filter
and Wheel
classes can be used to simulate
coronagraph observations in imaging mode.
-
class
coronagraph.imager.
Filter
(name=None, bandcenter=None, FWHM=None, wl=None, response=None, notes='')¶ Filter for telescope imaging mode.
Parameters: - name (string) – Name of filter
- bandcenter (float) – Wavelength at bandcenter (um)
- FWHM (float) – Full-width as half-maximum (um)
- wl (array) – Wavelength grid for response function (um)
- response (array) – Filter response function
- notes (string) – Notes of filter, e.g. ‘Johnson-Cousins’
-
class
coronagraph.imager.
Wheel
¶ Filter Wheel. Contains different filters as attributes.
-
add_new_filter
(filt, name='new_filter')¶ Adds new filter to wheel
Parameters: - filt (Filter) – New Filter object to be added to wheel
- name (string (optional)) – Name to give new filter attribute
-
plot
(ax=None, ylim=None)¶ Plot the filter response functions
Parameters: ax (matplotlib.axis (optional)) – Axis instance to plot on Returns: ax – Axis with plot Return type: matplotlib.axis
Note
Only returns an axis if an axis was not provided.
-
-
coronagraph.imager.
read_jc
()¶ Read and parse the Johnson-Cousins filter files.
Returns: - filters (numpy.ndarray) – Array of filter response functions
- filter_names (list) – List of string names for the filters
- bandcenters (numpy.array) – Wavelength bandcenters for the filters [microns]
- FWHM (numpy.array) – Full-width at half max for the filters
-
class
coronagraph.imager.
johnson_cousins
¶ Instantiate a filter
Wheel
with the Johnson-Cousins filters (U, B, V, R, I).Example
>>> jc = cg.imager.johnson_cousins() >>> jc.plot(ylim = (0.0, 1.2))
-
coronagraph.imager.
read_landsat
()¶ Read and parse the LANDSAT filter files.
Returns: - wl (list) – List of wavelength grids for each filter [microns]
- response (list) – Filter responses for each filter
- LANDSAT_names (list) – Names of each LANDSAT filter
- FWHM (numpy.array) – Full-width at half max for the filters
- bandcenters (numpy.array) – Wavelength bandcenters for the filters [microns]
-
coronagraph.imager.
read_jc2
()¶ Read and parse the Johnson-Cousins Bessel filter files.
Returns: - filters (numpy.ndarray) – Array of filter response functions
- filter_names (list) – List of string names for the filters
- bandcenters (numpy.array) – Wavelength bandcenters for the filters [microns]
- FWHM (numpy.array) – Full-width at half max for the filters